Well known is an electro-photographic type printer that detachably accommodates a process cartridge including a photosensitive member cartridge and a developing cartridge. The photosensitive member cartridge includes a photosensitive drum, and the developing cartridge includes a developing roller for supply toner to the photosensitive drum.
One of such conventional photosensitive member cartridges mountable in such electro-photographic type printer includes a photosensitive drum, a scorotron charger disposed upward of the photosensitive drum to oppose the same, a transfer roller disposed downward of the photosensitive drum, and a cleaning brush disposed rearward of the photosensitive drum.
This photosensitive member cartridge includes a drum casing on which an electrode member is provided for applying bias to the transfer roller. The electrode member is configured to be in contact with a resilient power feeding member disposed in a main casing of the printer. The electrode member is disposed on the drum casing such that the electrode member is in abutment with an end surface of a roller shaft of the transfer roller in a lateral direction.
The transfer roller is supported to the drum casing so as to be movable relative to the same. The transfer roller is prevented from moving upward due to its contact with the photosensitive drum. Further, the transfer roller is biased toward another end surface opposite to the end surface in the lateral direction, together with the electrode member, due to a resilient force of the power feeding member. The transfer roller is thus positioned in the lateral direction.